I think I didn't answer you before because first of all, you have the answers - lots of light, warmth, humidity fertilizer and plenty of water when the weather is warm.
Here's the thing, nobody wants to discourage you, but you're trying to grow tropical plants as house plants that really aren't all that well suited to being house plants. They need a greenhouse with tons of light (glass roof) warmth and humidity like what they have in nature to grow and bloom. They need to get big and grow healthy mature growths to bloom.
My variegated Alpinias have only bloomed for me after they're pretty mature. We had a couple of cold winters in a row where we got frost that killed them to the ground, and it then took them 3 years to recover and bloom again. They grow new leaves one year, then if the conditions are good and they don't die back from a cold night in the winter, those stems might flower the next summer.
Where you are, Minnesota, right? it's not unheard-of to get cold nights (below 50deg.) in May and even in August, right? So you have two months in between there for your plants to grow with good natural light and warmth, where my plants have 8 months of the year that they grow new shoots.
I think you will wait years, if ever to see flowers on those gingers. Sorry! Just my opinion. Anne?
@Xeramtheum What do you think?
